(1) Field of the Invention
The present invention relates to an adhesive tape cutting method for cutting, along a contour of a ring frame, a supporting adhesive tape joined to the ring frame so as to allow the ring frame to hold a semiconductor wafer, and an apparatus using the same. In particular, the present invention relates to a technique of detecting a cutting failure about the adhesive tape and cutting the adhesive tape along the ring frame with good accuracy.
(2) Description of the Related Art
A semiconductor wafer (hereinafter, simply referred to as a “wafer”) having a front face on which a circuit pattern is formed has been made thinner in thickness by back grinding. The wafer subjected to the back grinding is transported to a mount apparatus. In the mount apparatus, the wafer is joined to and held by a ring frame through a supporting adhesive tape. Herein, a disc-shaped cutter blade capable of rotating freely is pressed against the strip-shaped adhesive tape joined to the ring frame and the wafer positioned at a center of the ring frame; thus, the adhesive tape is cut along a contour of the ring frame (refer to JP-A 62-174940).
In recent years, the ring frame tends to be reused positively. In the ring frame to be reused, occasionally, a groove is formed on a side, at which the adhesive tape is joined, due to the contact with the cutter blade or the side is slightly warped. If an adhesive tape is joined to such a ring frame, a flatness of the adhesive tape can not be kept. Consequently, even in a case where the adhesive tape is cut while a predetermined pressing force is applied to the cutter blade, the cutter blade does not always penetrate the adhesive tape. Thus, there arises a problem of a cutting failure, that is, the cutting blade can not perfectly cut the adhesive tape.